The present invention relates to a composition and method of applying a curable polymer or prepolymer, for example, an amine curable polymer or prepolymer, to the surface of a cured and damaged elastomer substrate that has been chemically treated. More specifically, the present invention relates to bonding a urethane polymer at ambient temperatures to a cured rubber substrate with a chemically treated surface; the total system, polymer, and treating agent, is liquid in nature.
Heretofore, elastomer tire treads have been bonded to a rubber carcass by conventional procedures. Moreover, elastomer or rubber tires, such as automotive passenger tires and especially off-the-road tires such as those used in construction and mining operations, have been subject to damage such as cuts, gouges, lug loss, and the like. Naturally, such injuries weaken the tire; these tires have been treated with various items such as plugs, boots, and the like. However, the repair is usually not as strong as the original tire and often times failure of the tire occurs again at a later point in time.
Considering the prior art, U.S. Pat. No. 3,755,261 to VanGulick relates to complexes of 4,4'-methylene dianiline and/or racemic 2,3-di-(4-aminophenyl) butane with salts which have replaced MOCA in the curing of various amine curable prepolymers or polymers as, for example, urethane polymers or prepolymers. Cure is effected by heating the polymer or prepolymer to a temperature of about 90.degree. C. to about 182.degree. C.
U.S. Pat. No. 3,888,831 to Kogon relates to various polar compounds containing no reactive hydrogens which may be utilized in effecting ambient or room temperature cures of various amine curable polymers in the presence of complexes of MDA or racemic 2,3-di-(4-aminophenyl) butane and salts thereof.
U.S. Pat. No. 3,834,934 to Broisman relates to an adhesive composition in bonding rubber to reinforcing fiber which primarily consists of a conventional R-F-L adhesive, that is a resorcinol-formaldehyde-latex containing a small amount of a triallyl cyanurate composition having from 0.05 to 3 percent ring-bond chlorine. However, as readily apparent from the bottom of Column 2 and the top of Column 3, the cyanurate compound utilized by Broisman is different from applicant's in that the chlorine is directly bound to the carbon atom, whereas in applicant's trichloroisocyanuric acid, the chlorine is bound to the nitrogen atoms. As set forth in Volume 20, page 666 of the 2nd Edition of Kirk-Othmer Encyclopedia of Chemical Technology, cyanuric chloride reacts like an acid chloride that is quite different from N-chlorinated derivatives which are active chlorine-containing compounds. Hence, Broisman relates to an entirely different cyanurate compound which constitutes but a very small portion of the R-F-L adhesive composition.
U.S. Pat. No. 3,644,256 also to Broisman is very similar to U.S. Pat. No. 3,834,934 and hence is not pertinent for the reasons set forth immediately above.
U.S. Pat. No. 3,718,587 to Bhakuni et al. relates to cyanuric acid derivatives as adhesive promoting agents applied to tire yarn as a means of promoting adhesion between the cord and the rubber when used in conventional R-F-L adhesives. Hence, this patent fails to teach any suggestion of a chlorinated acid derivative and its utilization in treating an elastomer substrate.
U.S. Pat. No. 3,779,794 to DeSantis relates to a moisture-curable polyurethane sealant-primer system which utilizes various blocking agents which are relatively volatile at room temperature.
U.S. Pat. No. 4,085,283 to Den Otter et al relates to flame retardants utilizing cyanuric acid derivatives.
U.S. Pat. No. 4,143,454 to Utsunomiya et al. relates to a method of fixing connected parts of a rubber offshore structure. The application of a liquid rubber to a rubber is disclosed. An aqueous treating solution is utilized to treat the elastomer surface.
U.S. Pat. No. 4,158,378 to Pearson relates to the application of a polyurethane tread to a rubber tire carcass utilizing basically polycaprolactone polyols. Applicant's treating compounds are not disclosed.
An article entitled "Room Temperature Vulcanizing Adhesive Based on Ethylene-Propylene-Diene Terpolymer," Cantor, Uniroyal, Paper No. 18 presented to the Division of Rubber Chemistry of the American Chemical Society, Denver, Colo., Oct. 10, 1973, relates to various oxidants such as those utilized by applicant, which effect ambient temperature cures of EPDM. However, none of these compounds have heretofore been utilized to effect a bond between an amine curable polymer or prepolymer and an elastomer substrate.
Hughson Chemical Division, Lord Corporation, Product No. TS-2682-71, a surface primer for elastomeric substances is a proprietary compound, thought to be mono-, and/or dichloroisocyanuric acid. However, the primer is used only to enhance bonding of rubber to rubber or rubber to metal surfaces.
U.S. Pat. No. 4,136,219 to Odam relates to two methods or processes for applying polyurethane paint to vulcanized rubber parts. In one method, the rubber surface is sensitized by a benzophenone spray. In the other process, a resin cure is utilized for the rubber which is activated by the addition of halogenated rubbers. Totally lacking from this patent is any suggestion of an adhesive treating material as utilized by applicant.
U.S. Pat. No. 3,991,255 to Blaskjiewicz et al describes the adhesion of a polyurethane to an EPDM surface utilizing various chemical adhesives such as N,N-dihalosulfonamide or a cyclic N-haloamide including trichloroisocyanuric acid. However, an elevated temperature is needed to cure the EPDM as well as to bring about the reaction between said EPDM and the adhesive compound. Thus, it does not relate to any ambient temperature cure as in the present application.
British Pat. No. 1,352,645 relates to N-halogen sulphonamide treating agents which halogenize surfaces of synthetic and/or natural rubbers with a halogen donor in order to render these surfaces more effectively glueable to rubber or other materials.
U.S. Pat. No. 4,125,522 to Becker merely relates to a polyurethane adhesive in which a mixture of a methylenedianiline/sodium chloride complex is utilized at a temperature of 70.degree. C.
U.S. Pat. No. 3,966,530 to Cutts et al relates to various triazoline diones which are utilized in lieu of chlorinated or halogenated donors for treating elastomeric surfaces to improve adhesion.